If an organisation has decided to move company processes, applications and data into the cloud, it first has to decide which infrastructure to use and how the apps and data will be hosted and distributed. Businesses that want to use cloud computing have a choice of using a private or public cloud, or a mixture of the two in the form of a "hybrid" cloud.
This HP whitepaper looks at the benefits of using private cloud services and comes after a previous whitepaper looking at the benefits of public cloud services. It will be followed by another whitepaper outlining the advantages of using hybrid cloud solutions.
Private and public
The main difference between private and public cloud infrastructures is that a private system is used only to house and distribute your data and applications, while a public model is used to serve the requirements for multiple organisations, not just yours.
A public cloud usually sees a service provider make available applications, data storage capacity and other resources to organisations or the general public using its own servers. With a a private cloud, organisations build the infrastructures themselves using their own servers, or they can bring in a third party to build and deliver the dedicated resources they need.
Companies deciding which type of cloud to use first have to consider how critical the data and applications are to their business. They must also consider any regulatory or data protection requirements relevant to their organisation. Organisations in financial services or health, for instance, must comply with strict rules regarding the control and security of their data, so they are more likely to choose a private cloud service.
Secure private cloud infrastructures
One main advantage of private cloud infrastructures is that they are usually more secure than alternatives, since the organisation's data is tightly secured and controlled on servers that no other company has access too.
The servers can either sit within the network boundaries of the organisation using them, with those servers managed and maintained by internal IT staff, or they can be located within the data centre of a cloud service provider, with an organisation accessing the data stored on the servers via private and secure network links.
If the servers that form part of private cloud infrastructure are located in company premises though, an organisation does not have to worry about the physical security of servers situated in the external data centres of third party cloud providers. Although it must be said that data centres used by cloud service providers are increasingly having to meet strict data security compliance requirements.
Other organisations in less sensitive industries, or organisations that need cloud services quickly and cheaply to deal with less critical data, are more likely to choose a public shared cloud infrastructure.
As well as greater security, private clouds can often offer enhanced and more predictable service availability for users, supported by more fault tolerant network backbones. Such reliability can sometimes be lacking when public and shared cloud networks are used, which is why organisations using any cloud service must first evaluate what network performance they will see for the type of applications and services they are putting into the cloud.
Cost vs flexibility
As private clouds can be built around large dedicated infrastructures, with organisations installing their own servers and storage hardware, by their very nature they can involve significant investments to get off the ground. However, private clouds allow organisations to have the greater flexibility to shift workloads among those servers as they see spikes in usage or when they deploy new applications. Unlike with public clouds, they don't have to ask a cloud service provider first before they make any changes.
It must be remembered that when using a cloud service provider in the public cloud, there will be a service contract, which may or not guarantee the service levels or workload flexibilities that may be needed to serve the business. Private cloud infrastructures should usually deliver a streamlined process to the organisation when it comes to changes, as it is their staff that are usually making them.
Air France chooses a private cloud
One company that has recently plumped for a substantial private cloud is Air France. The company says it has automated and increased the reliability of its 1,500 Linux servers by deploying a private cloud solution. This is based on HP's Cloud Service Automation (CSA) software to accelerate deployment times for physical and virtual infrastructures.
With between 350 and 500 installations and re-installations annually, Air France says its Linux server farm is growing rapidly. With the resource costs incurred by these installations, it became necessary to standardise on a single tool to automate the deployment of operating systems, middleware, monitoring tools and capacity management.
Read more: How the cloud supports green IT computing
The HP solution has significantly reduced the time it was taking to bring IT environments into service "while improving quality and reducing operational costs", said Air France.
"Since automating our installation processes, we have gone from around six days for installing a server cluster to one day and, instead of more than 24 hours, it now takes less than 15 minutes to install one virtual machine," said Patrick Bourel, the head of open systems at Air France.
Air France says that its private cloud paid for itself within a year, which clearly demonstrates the potential for private clouds to not only deliver greater security and potentially quicker business agility, but also support the business in a cost-effective way.